Detonators in which delay times, activating signals etc. are controlled electronically, are generally placed in the category electronic detonators. Electronic detonators have several significant advantages over conventional, pyrotechnic detonators. The advantages include, above all, the possibility of changing, or “reprogramming”, the delay time of the detonator and allowing shorter and more exact delay times than in conventional, pyrotechnic detonators. Some systems with electronic detonators also allow signalling between the detonators and a control unit.
However, prior-art electronic detonators and electronic detonator systems suffer from certain restrictions and problems.
A detonator system has to be easy and flexible to handle and the risk of misapplication must be reduced to a minimum. At the same time, there is a need for flexible, electronic detonator systems, with a possibility of detailed function and status check and which allow high-resolution and reliable delay times, as well as continuous monitoring of the condition of each detonator. Detonators which are included in such a system should be inexpensive since they necessarily are disposable.
A problem of prior-art electronic detonator systems is that it has often been necessary to weigh up, on the one hand, the functionality of the system in terms of control capabilities and, on the other hand, the cost of a detonator included in the system.
Prior-art electronic detonator systems also have a restriction as regards the preparation of the detonators which has been time-consuming, which means that in practice the number of detonators which could be connected to one and the same system has been limited. The number of detonators in one and the same system has also been limited due to the fact that too high signal levels have been required for communication in a system with many detonators. The more detonators included in the system, the more difficult to communicate with the “last” detonator.